1 locate the back piece and the two screws and plates on the sides holding it on its place
2 screw those out
3 slide the back piece out of its place
4 change the buckle
5 put the back piece back on, remember to check that the forward lean thingy in the back is still on there, it might slip out
6 when the piece is on its place, put the screws on and tighten them
7 make sure everything is put together and no parts are missing
8 go ski

disclaimer: i haven't done it in a while cause i don't have ft's anymore, but i had to change them 5+ times and that's how i remember doing it. hope this helps!

1 locate the back piece and the two screws and plates on the sides holding it on its place
2 screw those out
3 slide the back piece out of its place
4 change the buckle
5 put the back piece back on, remember to check that the forward lean thingy in the back is still on there, it might slip out
6 when the piece is on its place, put the screws on and tighten them
7 make sure everything is put together and no parts are missing
8 go ski

disclaimer: i haven't done it in a while cause i don't have ft's anymore, but i had to change them 5+ times and that's how i remember doing it. hope this helps!